This is much delayed, and perhaps those who were asking don't care by now,
or have left the List. But there really are cassettes available which
presewnt readings of classical Greek (including pitch accents).

They are read by Prof. Stephen Daitz, Prof, of Classical Languages
at CUNY. They include:
"The Pronunciation and Reading of Ancient Greek: A Practical Guide"
(two cassettes plus booklet--readings from Homer and Plato, plus exercises)
@ $34.95